The invention relates to a tongue plate assembly for a seat belt system and, more particularly to a tongue plate assembly having an anti-rattle construction and a method for making the same.
Tongue plate assemblies that latch into buckles for securing a seat belt about an occupant of a vehicle seat are usually made from a stamped-metal tongue plate in which the tongue plate has a hard plastic insert located at an elongated, laterally extending opening in a wide portion of a plate body for the seat belt webbing. In many seat belts systems, the tongue plate assembly typically is positioned between the side trim of the vehicle and the outboard side of the vehicle seat when in the unlatched or stowed condition. In some recent model vehicles, there has been a gradual reduction in the amount of space between the side of the vehicle seat and the side trim of the vehicle interior. In some instances, the seat belt twists and positions an edge of the tongue plate assembly to engage a pillar or side rim in the vehicle. Accordingly, when the vehicle is undergoing rough ride conditions, the tongue plate assembly is more likely to shake and vibrate on the belt webbing and engage against the hard side trim panel in the vehicle interior generating undesirable noise in the vehicle compartment.
U.S. Pat. No. 6,837,519 (incorporated by reference herein) is directed to a non-cinching tongue plate assembly having a latch plate with a coating of hard plastic material over molded onto the plate. In a cinch tongue plate assembly, a slidable cinch member or portion is a distinct, discrete member which is slidably mounted for movement relative to the tongue plate body to cinch or grip the belt passing through the assembly such as described in U.S. Pat. Nos. 4,480,854 and 4,588,207 (both incorporated by reference herein). As described in the latter patent, a slidable cinch member is free falling along the belt until the seat belt is latched; and after latching, the cinch portion grips the belt to limit free transfer between the shoulder belt portion and the lap portion. In a typical cinch-type tongue plate assembly, the slidable cinch member has top and bottom sides extending over the top and bottom sides of the tongue plate and has outer side edge portions wrapped about the outer side edges of the tongue plate. Thus, there is a need for providing noise reducing material on the cinch member, and particularly the side edges thereof which are projecting laterally outwardly relative to the tongue plate body.
The non-cinch, tongue plate assembly of the '519 patent lacks a slidable clinch member slidably mounted on the tongue plate body. In the '519 patent, it is stated that while the hard plastic is being molded onto the tongue plate and is still warm, a soft plastic over molded onto the warm, hard plastic material on the plate. While providing noise reduction, over molding two coatings of plastic material onto the latch plate assembly undesirably increases the manufacturing costs for the latch plate. In this regard, two insert molds need to be employed into which the operator has to manually load the part onto which the over mold is to be applied. So in the latch plate assembly disclosed by the '519 patent, there is a first insert mold in which the operator places the plate body for having the hard plastic over molded thereon. Thereafter, with the hard plastic still warm, the operator removes the plate body with the warm over mold of hard plastic, and places it in the next insert mold. This insert mold is then cycled for over molding the soft plastic material onto the warm, hard plastic material. As is apparent, the two insert molds require significant operator intervention for generating the over molded latch plate assembly of the '519 patent.
Accordingly, there is a need for an anti-rattle, tongue plate assembly having a distinct, discrete cover member, particularly for a cinch type of tongue assembly having a slidable cinch member on a tongue plate body and having an anti-rattle construction. The tongue plate assembly with the distinct, discrete cover member may improve the manufacturing cost efficiencies for the anti-rattle construction.